"Total Cross-section" is related to the absorbance of the light intensity through Beer-Lambert's law. It is the sum of all cross-sections corresponding to the various reactions or processes between an incident particle of specified type and energy and a target particle.
Applicable units are those of quantitykind:Area
http://en.wikipedia.org/wiki/Cross_section_(physics)
"Total Cross-section" is related to the absorbance of the light intensity through Beer-Lambert's law. It is the sum of all cross-sections corresponding to the various reactions or processes between an incident particle of specified type and energy and a target particle.
http://www.iso.org/iso/catalogue_detail?csnumber=31895